Persons, either male or female who hang out on the roof of off-campus student houses, undergraduate societies, or fraternities. Usually members of said house. Usually on some sort of drugs such as shrooms or trying to smoke a Joint on the sly.

Named because they are frequently spotted in packs and usually only the top part of their body is visible from the ground below.

I walked up to ******** after class and I saw three roof gnomes pop their heads out to see who was coming up the walkway.